Crimping machine



Feb. 9, 1965 K. G. SMITH 3,168,918

CRIMPING MACHINE Filed June 1, 1962 IN VEN TOR:

Ke/ vi 6 ora'on 8m 17/7 ATT0RNEY United States Patent ()fiice 3,168,918Patented Feb. 9, 1965 3,163,918 CRIMPIYG MACHINE Kelvin Gordon Smith,Strettord, England, assignor to Associated Electrical industriesLimited, London, England, a British company Filed June 1, 1962, Ser. No.199,370 Claims priority, application Great Britain, June 8, 1961,20,765/ 61 3 Claims. (Cl. 153-11) This invention relates to crimping andhas in view a power-operated crimping machine eminently suitable forcrimping terminals on to electric cables.

Thepresent invention provides a power-operated crimping machine, such asfor crimping terminals on to electric cables, comprising ahydraulically-operable ram and cooperating die or anvil havingrespective cooperating parts thereof shaped in accordance with theconfiguration to be applied by crimpage to a cable terminal or otherassembly introduced between the ram and anvil, and pump means forapplying hydraulic pressure of a high order to said ram in the closedcondition of solenoid-operat'ed hydraulic valve means which can beopened at the end of a crimping operation to release said hydraulicpressure.

The pump means is preferably motor driven and may comprise a swashplatetype pump or other pump having a fixed or adjustable constant strokecapable of providing hydraulic pressures of the order of 10,000 lbs. persquare inch.

The maximum hydraulic pressure required for crimping may be pre-setpreferably by suitable adjustment of a pressure-responsive switchconnected in the hydraulic pressure system and effective upon thepressure reaching the pre-set value to bring about the opening of thesolenoid-operated hydraulic valve means.

The crimping machine according to the invention in one exemplary formthereof comprises an electrical control circuit in which the energizingcoil of a normally open solenoid operated hydraulic valve is connectedto an alternating current supply via a control switch (e.g. footoperated) having normally open contacts.

By way of example one embodiment of the present invention will now bedescribed with reference to the accompanying drawing, in which:

FIG. 1 is a schematic diagram of a power-operated crimping machine; and

FIG. 2 is a diagram showing in detail the electrical control circuit ofthe machine illustrated in FIG. 1.

Referring to FIG. 1 of the drawing, the crimping machine comprises aconstant stroke oil pump 1, driven continuously by an electric motor 2supplied with current through a starter 3 and an isolator 4 from athreephase supply 31. The oil pump 1 includes a rotary valve 5 arrangedto be actuated from the open position, as illustrated, to a closedposition by the energization of a solenoid 6 and the consequent rotationof a valve spindle 7 imparted through a linkage 8. The rotary valve 5 isconnected in a hydraulic pressure system including a pipeline 9extending to a ram 10 movable in a cylinder 11. The ram 11} co-operateswith a die or. anvil 12 and the co-operating surfaces of the ram and dieare shaped according to the configuration to be applied by crimpage to acable terminal assembly for example introduced between the ram andanvil.

The pipeline 9 includes an adjustable pressure-responsive changeoverswitch 13, the moving contact 14 of which is displaced counter-clockwiseas viewed in the drawing from its normal position as hydraulic pressurebuilds up in the pipeline 9. The solenoid 6 and an electromagneticrelayunit 10', the function of which will be described later are arranged tobe supplied with current from a single-phase current supply SP under thecontrol of the pressure-responsive changeover switch 13 and afoot-operated control switch (FIG. 2) having normallyopen contacts 15.

Referring now to FIGS. 1 and 2 of the drawing, it will be seen that therelay unit 10 has an energizing winding 16 with a pair of normally-opencontacts 17 and 18 and that neither the relay 10 nor the solenoid 6 foractuating the rotary valve 5 to its closed condition will be energized.The valve 5 being open prevents the build up of hydraulic pressure inthe pipeline 9 by the continuously operating constant stroke pump 1,while the moving contact 14 of the pressure-responsive switch 13 ismaking contact with a non-adjustable fixed contact of the switch 13signifying zero hydraulic pressure.

A cable-terminal assembly (not shown) to be crimped is positioned on thedie or anvil 12 of the crimping machine and the foot-operated controlswitch is then operated so that contacts 15 close. The operation of thecontrol switch completes an energizing circuit through closed contacts15 for the relay unit 10' which, in operating, causes the solenoid 6 tobe energized over closed contacts 17. The solenoid 6, in operating,eliects closure of the hydraulic valve 5 to allow the hydraulic pressureto build up. The energizing circuit for the relay unit 10' includes aload resistor 19 as well as the co-operating moving contact 14 andnon-adjustable fixed contact of the pressure-responsive switch 13 andthe relay It), in operating, completes its own holding circuit by theclosure of normally-open contact 18. Thus the relay 10 will bemaintained in its energized condition and hence maintain the valve 5closed upon the interruption of the initial energizing path for therelay 10 (i.e. through the contacts of the pressure-responsive. switch13) as the hydraulic pressure builds up and the moving contact 14 of thepressure-responsive switch 13 disengages the nonadjustable fixedcontact. g

The hydraulic pressure increases, forcing the ram 10 downwards 'intoengagement with the cableterminal assembly positioned on the anvil 12,while the moving contact 14 of the pressure-responsive switch 13movestowards the adjustable fixedcontact of the switch which will have beenpre-set to provide the desired maximum hydraulic pressure. At thepre-set hydraulic pressure which may be 10,000 lbs. per square inch, themoving contact 14 of the pressure-responsive switch engages with theadjustable fixed contact and by so doing the relay unit 10' releases dueto the short-circuiting of its energizing winding 16 and consequentlythe energizing circuit of the solenoid 6 is interrupted by the openingof relay contacts 17 to bring about the opening of the valve 5 and theconsequent release of the hydraulic pressure exerted on the ram 10. Theram 10 under the action of a return spring (not shown) accordinglydisengages with the crimped cable-terminal assembly which can then bewithdrawn from the anvil 12.

If the hydraulic pressure fails to reach the maximum pre-set value, suchas may be occasioned for example by the failure of the pump 1, so thatthe moving contact 14 of the pressure-responsive switch 13 fails to makecontact with the adjustable. pre-set fixed contact and short-circuit therelay coil 16, the hydraulic pressure can be released to enable thecable-terminal assembly to be removed from the machine by disconnectingthe supply SP (FIG. 2) by switching means (not shown) so that thesolenoid 6 is deenergizedand the hydraulic valve 5 opens.

If an operator Wishes to stop the crimping machine atv any time duringthe crimping operation, he can operate a push button switch 20 (FIG; 1)to open the motor cirremains. Normally the switch 20 locks out andcannot be restored to its closed condition without the use of a key,

which for proper supervision,may be retained by a supervisor. By thisarrangement, an operator will be forced to disclose'the emergency to thesupervisor.

A magnetic safety switch having normally-closed contacts 21 in serieswith the contacts 20 may also be providedand fitted to a personnelsafety guard around. the ram and anvil assembly so that motor 2 cannotoperate unless the guard is effective.

The crimping stroke of the ram is set and maintained by the engagementof abutments on the cooperating parts of .the ram 10 and anvil 12 whenthe hydraulic pressure reaches a valve lower than the pre-set value,thus providing a safety pressure margin preventing any possibility ofbursting the cable-terminal assembly during crimpage.

To avoid damage to the machine in the event of excessive hydraulicpressures being built up, a spring-loaded safety value (not shown) maybe connected in the hydraulic system.

What I claim is:

1. A power-operated crimping machine comprising a hydraulic ram, a dieco-operating with said ram, surfaces on said ram and said die beingshaped according to the configuration to be applied by crimpage to anassembly introduced between said ram and die, continuously operatingpump means, driving means for said pump, a hydraulic pressure system,said pump means applying hydraulic pressure to said ram through saidsystem, hydraulic valve means for controlling the hydraulic pressureintroduced into said system, solenoid means for actuating said hydraulicvalve means, a source of energizing current for said solenoid means,manually operated switching means controlling flow of said current tothe solenoid means, adjustable switching means operable at the end of acrimping operation to efiect a change in the condition of'the solenoidmeans and thus the hydraulic valve means so as torelease the hydraulicpressure on said ram, said adjustable switching means being adjustableso that it operates when the maximum permitted hydraulic pressure isbeing applied to the ram.

2. A power-operated crimping machine comprising a hydraulic ram, a dieco-operating with said ram, surfaces on said-ram and said die beingshaped according to the configuration to be applied by crimpage .to anassembly introduced between said ram and die, continuously operatingpump means, driving means for said pump, a hydraulic pressure system,said pump means applying hydraulic pressure to said ram through saidsystem, hydraulic valve means controlling the hydraulic pressureintroduced into said system, solenoid means for actuating said hydraulicvalve means, manually operated switching means initially controllingflow of said current to the solenoid means, a holding circuit energizedby closing of the manually operated switching means for maintainingenergization of the solenoid means, a source of energizing current forsaid solenoid means and adjustable switching means operable at the endof a crimping operation to effect a change in the condition of theholding circuit and thus the hydraulic valve means so as to release thehydraulic pressure on said ram, said adjustable switching means'beingconnected in the hydraulic pressure system and being responsive to amaximum hydraulic pressure in said system to bring about the opening ofthe hydraulic valve means.

3. A power-operated crimping machine comprising a hydraulic ram, a dieco-operating with said ram, surfaces on said ram and said die beingshaped according to the configuration to be applied by crimpage to anassembly introduced between said ram and die, continuously-operatingpump means, driving means for said pump, a hydraulic pressure systemincluding said pump means, said pump means being capable of-applyinghydraulic pressure to said ram through said system, hydraulic valvemeans in said system for controlling the hydraulic pressure, solenoidmeans for actuating said hydraulic valve means, an electric relay forcontrolling the energization of said solenoid means, a source ofenergizing current for the solenoid means and said relay, said relaybeing arranged for response at the end of a crimping operation to effecta change in the condition of the solenoid means and thus the hydraulicvalve means, whereby to release the hydraulic pressure on said ram.

References Cited by the Examiner UNITED STATES PATENTS CHARLES W.LANHAM, Primary Examiner.

1. A POWER-OPERATED CRIMPING MACHINE COMPRISING A HYDRAULIC RAM, A DIECO-OPERATING WITH SAID RAM, SURFACES ON SAID RAM AND SAID DIE BEINGSHAPED ACCORDING TO THE CONFIGURATION TO BE APPLIED BY CRIMPAGE TO ANASSEMBLY INTRODUCED BETWEEN SAID RAM AND DIE, CONTINUOUSLY OPERATINGPUMP MEANS, DRIVING MEANS FOR SAID PUMP, A HYDRAULIC PRESSURE SYSTEM,SAID PUMP MEANS APPLYING HYDRAULIC PRESSURE TO SAID RAM THROUGH SAIDSYSTEM, HYDRAULIC VALVE MEANS FOR CONTROLLING THE HYDRAULIC PRESSUREINTRODUCED INTO SAID SYSTEM, SOLENOID MEANS FOR ACTUATING SAID HYDRAULICVALVE MEANS, A SOURCE OF ENERGIZING CURRENT FOR SAID SOLENOID MEANS,MANUALLY OPERATED SWITCHING MEANS CONTROLLING FLOW OF SAID CURRENT TOTHE SOLENOID MEANS, ADJUSTABLE SWITCHING MEANS OPERABLE AT THE END OF ACRIMPING OPERATION TO EFFECT A CHANGE IN THE CONDITION OF THE SOLENOIDMEANS AND THUS THE HYDRAULIC VALVE MEANS SO AS TO RELEASE THE HYDRAULICPRESSURE ON SAID RAM, SAID ADJUSTABLE SWITCHING MEANS BEING ADJUSTABLESO THAT IT OPERATES WHEN THE MAXIMUM PERMITTED HYDRAULIC PRSSURE ISBEING APPLIED TO THE RAM.